Religious pluralism is a term designating the peaceful co-existence and mutual acceptance of different religions. This is the opposite of fundamentalism, where followers of one religion fanatically insist that their view is the only and exclusive source of truth. Supporters of religious pluralism accept that different religions can give equally valid insights and are in favor of inter-religious co-operation.
Religious pluralism relies heavily on inclusivism, or the idea that one's religion is not the sole source of truth, and therefore other sets of beliefs can be at least partially true. It is based on tolerance, which is a prerequisite for the harmonious co-existence of different religious movements. One aspect of pluralism is ecumenism, the efforts meant to ensure greater unity and co-operation between denominations within the Christian religion.
History records many fierce feuds between religious movements. During the Middle Ages, between the 11th and 13th centuries various Popes, the head of the Christian church, called for a series of crusades to regain control over Jerusalem and the surrounding Holy Land from Muslims. These wars and related campaigns through south-eastern Europe and what is now the Middle East saw many atrocities and massacres committed by both sides. Another instance of religious intolerance is the Inquisition, which began in 12th century Europe, in which the church sought out and tested any suspected deviation from what it saw as the true religion, persecuting many Jews, Muslims and Christians.
The emergence of Protestantism, inspired by the teachings of Martin Luther (1483-1546) and John Calvin (1509-1564), also provoked a strong reaction from the established Roman Catholic church. Notably, there was the massacre of protestants in France on St. Bartholomew's Day in 1572, as French Calvinists, known as the Huguenots, were persecuted by the Catholics.
Contemporary society also has examples of religious intolerance. The Troubles is the name given to the 25-year civil conflict between Catholic and Protestant communities in Northern Ireland. Beginning from a series of peaceful civil rights protests by the disenfranchised, minority Catholic communities in Belfast and Londonderry, or Derry in the late 1960s, when law and order broke down, the British government sent in troops who would remain stationed in the province until after the signing of the Good Friday Agreement in 1998. When the British Empire planned its withdrawal from India in the 1940s, it decided to create Pakistan to provide a home country for Muslims separate from the majority Hindu population. Antagonism between the countries, and sometimes a state of war, has existed right from independence in 1947.
The Bosnian War between 1992 and 1995 was also largely based on religious differences between Muslims, Orthodox Serbs and Catholic Croatians. A thousand years after the first Crusade, territorial disputes in the Middle East, between the Jews established in the state of Israel, and the surrounding predominantly Muslim countries, as well as displaced Palestinians, continued in to the 21st century.
There have long been efforts toward peaceful co-existence and co-operation. The Roman Empire is an example of a polytheistic and pluralistic state, although for long periods any tolerance was as the result of the imposition of strict military force. It was not until the Edict of Milan in 313 A.D.E., for instance, that religious tolerance was proclaimed across the Roman Empire, forbidding the torture of Christians. The efforts to protect religious minorities include also the 1782 Edict of Toleration, issued by Joseph II, the emperor of the Holy Roman Empire, which protected the religious freedoms of non-Catholics, such as Calvinists and Lutherans. In 1787, France's King Louis XVI also ended the persecution of Huguenots by issuing the Edict of Versailles.
Religious pluralism is also an underlying motif in the U.S. Constitution, whose first amendment reads: "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
Religious pluralism can exist even at a personal level – that is religions can be reconciled not only at the level of the community but also at the level of the individual. Some religions allow their followers to associate with other religious movements. For example, Buddhist adherents can practice another religion as well, as Buddhism does not have supreme deities and it inherently tolerates pluralism. Likewise, inclusive Christianity also recognizes and honors non-Christian gods.